The largest study of the effect of exercise on women has shown that brisk walking for three to four hours a week (half an hour a day) reduced the incidence of heart attacks by a third - the same reduction achieved by those who took more vigorous exercise such as swimming, tennis or aerobics.
Most previous research on heart disease has been performed on men and advice for women based on science has been sparse. The size of the study, the length of the follow-up and its prospective design (looking forward rather than backward) mean its findings are likely to be reliable.
Researchers from Harvard Medical School and Brigham and Women's Hospital in the United States followed 72,000 nurses, aged 40 to 65 in 1986, for eight years. Over that period, 475 had heart attacks and another 175 died of heart disease. The more exercise the women took, the more their risk of heat attack fell. The calories used during different forms of exercise were measured so that the total energy expenditure could be assessed. The only advantage of vigorous exercise was that it took half as long to perform.
The study, published in the New England Journal of Medicine, says it is "biologically plausible" that moderate and vigorous exercise have the same effect in cutting heart attack risk. Several studies have shown that both have similar effects on blood pressure, fat concentrations in the blood and insulin sensitivity.Reuse content